Furnace door frame



Feb. 6, 1934. R. J. SCHADE FURNACE DOOR FRAME Filed Aug. 11, 1932 Patented Feb. 6, 1934 rrso STATES PATENT OFFICE 2 Claims.

This invention relates to improvements in furnace door frames for open-hearth furnaces, or the like, and it is among the objects thereof to provide a door frame structure which shall be of 5 relatively inexpensive construction and economical in its use.

Door frames for open-hearth furnaces are of hollow construction to provide for the circulation of a cooling medium interiorly of the frame to prevent deterioration caused by the excessive heat to which the frames are subjected. A conventional type of frame is a hollow cast steel structure in which the front, side and rear walls of the frames are integrally cast.

The difficulty with this construction is the rapid deterioration and burning out of the rear wall which is adjacent the heating chamber of the furnace. The burning out of the rear wall is caused by the inefficiency of the cooling medium to maintain a normal temperature on account of the relatively thick wall required in a cast structure and also on account of the high porosity of a casting.

Another conventional form of hollow door frame structure is one constructed of metal plates which are welded together to form a hollow structure, and this construction has the advantage of utilizing a thinner gauge metal which may be more effectively cooled to prevent rapid deterioration. However, the all metal plate form of door frame does not possess the strength and rigidity of the cast steel frame and is readily distorted when subjected to blows in handling the charges through the door frame opening.

" In accordance with the present invention it is proposed to employ a composite form of furnace door frame which is constructed of a steel casting in which the door guide and the opening walls are integrally formed with the front plate, and

a relatively thin metal plate is welded to the rear of the casting to constitute the rear wall of the door frame. By means of this construction the desirable properties of the cast steel frame and the all metal platestructure are combined in that the resultant'frame will have the strength and ri Ldity of the cast steel structure and the efficient cooling effect of the metal plate rear wall which is renewable as the plate can be readily attached by welding it to the casting.

The features of the composite furnace door frame structure will become more apparent from a consideration of the accompanying drawing forming a part hereof, in which like reference characters designate like parts and in which Figure 1 is a front elevational view of a door frame structure embodying the principles of this invention; Figure 2 a sectional elevational view thereof taken along the line IIII of Figure 1: Figure 3 a bottom plan view and Figure 4 an enlarged the door frame and is fitted into off-set portions detail of a joint illustrating the manner of joining the rear steel plate with the front casting.

With reference to the several figures of the drawing, the structure therein illustrated comprises a casting 1 having a rearwardly curved portion 2 shown in Figure 2 constituting the upper edge of the door opening, an offset shoulder 3 forming the door frame, and outer sides constituting the end walls 4, all of which are integrally formed in a unitary casting member.

A black plate generally designated by the reference numeral 5 is cut out to the dimensions of the door opening and the outer dimensions of 6 and '7, Figure 4, the shoulder '7 being chamfered as is also the back plate 5 for receiving the welded metal 8 therebetween to form a strong joint.

The interior of the hollow casting is provided with a circulating system of piping generally designated by the reference numeral 9 which does not constitute any part of the present invention. By means of the circulating system, the hollow interior of the frame constituted by the casting 1 and the rear plate 5 is a water cooled chamber in which the cooling fluid is circulated to keep the metal of the casting l and particularly the rear plate 5 from heating excessively.

As is indicated by the weld 8 in Figure 3, the rear plate 5 sets in the shoulders 7 of the casting and forms a rigid construction that reinforces the edge walls a and the wall 2 forming the opening of the frames and by means of the combining of the metal plate with the castings in the manner described, the entire structure is rendered rigid and durable.

It is evident that the steel plate 5 will stand up longer than the back wall of a solid cast frame as the surface is of less porosity than the casting and the plate can be thinner in cross-section than the cast wall, thus rendering the cooling medium of the interior of the frame more effective in keeping the rear wall at normal temperatures.

I claim:

1. A composite furnace door frame comprising a front wall having a peripheral flange constituting integrally cast side, top, bottom and dooropening walls, and a sheet metal plate abutting said peripheral flange joined thereto by welding to form a rear wall said rear wall being of less cross-sectional area than the cast wall.

2. A composite furnace door frame comprising a front wall having a peripheral flange constituting integrally east side, top, bottom and dooropening walls, and a sheet metal plate joined to said flange to form a rear wall, said flange having its edge provided with a shoulder for seating said rear wall and said rear wall being welded'in said shoulder.

RALPH J. SCHADE. 

